... oil cylinderMaterialSteel,20#,45#,Aluminium, bronzeComposeHydraulic body, Hydraulic piston, Hydraulic RodHydraulic clinder typesPiston,plunger,piston, telescopic,SwingoutInside Surface roughnessRa 0.4---0.8 ... hard steel body prevents the hydraulic fluid from escaping.Hydraulic PistonThis is another component of hydraulic cylinder. The hydraulic piston is a round component ...